Packaging machines which enclose packages in shrink wrap film are in common use today. In most instances, these types of machines are low volume products and are hand assembled because they are not manufactured in sufficient numbers to justify automated and expensive tooling. In order to be successful, these packaging machines must accommodate a wide variety of package sizes which require various widths of packaging film. Most, if not all, of these machines require a heating unit for shrinking the film to provide a tight abutting contact between the film and the package. In general, this type of packaging machine includes a platform for initially wrapping the package, a package sealing station where the edges of the film are cut and sealed and a heating station which shrinks the film around the package. Because the machine must accommodate a wide variety and size of the packages, these three stations must be relatively movable with respect to each other so that a package being processed will travel along a path that will be at or near a center line of the heating tunnel so that uniform heating and shrinking of the film around the package will be achieved.